Phase 1 Results

A first set of pilot tests with variable speed limits (VSL) for traffic and environmental purposes was carried out in the first project phase (April 2017 – April 2018). Variable limits were imposed by means of Variable Message Signs positioned along the test stretch of the highway.

First results are encouraging!

From an environmental point of view the first empirical measurements have highlighted that an average reduction of 15 [km/h] of the average speed of light vehicles, compared with the normal flow of traffic with speed limit at 130 [km/h], determines a reduction of 10% of the average concentration of NO2 (nitrogen dioxide) at the roadside of the highway.

From a traffic point of view, in nearly saturated conditions, the application of VSL has determined an increase of the capacity of the highway. More specifically, under these conditions it has been empirically estimated an increase of 8% of the number of vehicles passed through the test stretch. Compared to standard conditions, VSL have confirmed to determine a better traffic fluidity, determining therefore a reduction of the traffic jams, of the stop&go situations and of the travel times.